The present invention relates generally to gas generating systems and, more particularly, to gas generators used in vehicle occupant protection systems and related components, such as seatbelt pretensioners.
Gas generators used in seatbelt pretensioners are known as micro gas generators due to the relatively small size of the gas generator. Exemplary pretensioners using such micro gas generators include those described in U.S. Pat. Nos. 6,460,794, 6,505,790, 6,520,443, and 6,419,177, incorporated herein by reference. Micro gas generators generally include an initiator holder for receiving and securing an initiator therein, an initiator including an initiator charge, and a gas generant composition which ignites and burns in response to activation of the initiator to produce gases for actuating the seatbelt pretensioner.
In addition, conventional micro gas generator designs usually incorporate a casing secured to the initiator holder for containing the gas generant therein and for positioning the gas generant in proximity to the initiator. The casing is secured to the initiator holder by crimping, using deformable crimp tabs machined into the structure of the holder. An O-ring or some other type of compressive seal may also be required to seal the interface between the casing and the holder.
Machining of the crimp tabs and of surfaces along the initiator holder for positioning the casing therealong increases the manufacturing complexity and cost of the initiator holder. The need for a separate compressive sealing element in the crimped design also adds to the cost of the micro gas generator assembly.